Surgical treatment of a comminuted articular fracture of the accessory carpal bone in a thoroughbred horse

Computed Tomographic Documentation of a Comminuted Fourth Carpal Bone Fracture Associated with Carpal Instability Treated by Partial Carpal Arthrodesis in an Arabian Filly

OBJECTIVE

To report treatment of a unilateral comminuted fourth carpal bone (C4) fracture associated with carpal instability by partial carpal arthrodesis (PCA) of the middle carpal joint (MCJ) and carpometacarpal joint (CMCJ).

STUDY DESIGN

Case Report.

ANIMALS

An 8-month-old Arabian filly.

METHODS

A C4 slab fracture was diagnosed radiographically; however, fracture comminution was conclusively diagnosed after computed tomographic (CT) imaging. PCA of the MCJ and CMCJ was performed with 2 narrow dynamic compression plates.

RESULTS

PCA provided appropriate carpal stability and correct limb alignment immediately after surgery. Complete bony fusion with substantial carpal flexion and no lameness at walk or light trot was observed 8 months after surgery.

CONCLUSIONS

Carpal CT was successfully used to define fracture configuration after standard radiographic examination failed to delineate comminution. PCA was selected because of joint instability and lateral carpal collapse of MCJ and CMCJ and can be successfully used to treat comminuted C4 slab fractures associated with carpal instability. Moderate MCJ osteoarthritis without radiocarpal joint involvement allows pain-free, substantial carpal flexion and thus, return to low-level pleasure riding may be possible.

CLINICAL RELEVANCE

CT imaging may more adequately characterize traumatic carpal bone injury, particularly, when carpal bone fracture configuration cannot be determined on standard radiographs. Early PCA of the MCJ and CMCJ is an useful alternative to treat comminuted C4 slab fractures that cannot be reconstructed.

Treatment of a second carpal bone fracture by removal under ultrasonographic guidance in a horse

OBJECTIVE

To report an unusual 2nd carpal bone (C2) slab fracture and its treatment, using an ultrasonographically assisted, minimally invasive arthrotomy technique, for fragment removal.

STUDY DESIGN

Case report.

ANIMALS

An 11-year-old crossbred Warmblood gelding.

METHODS

A bone fragment, spanning the height of C2, identified on the palmaromedial aspect of C2 was demarcated intraoperatively using ultrasonographically guided needles and removed by arthrotomy.

RESULTS

Fracture fragment removal was achieved using a small, ultrasonographically guided arthrotomy. The horse has become sound after treatment and returned to the previous level of pleasure riding activity.

CONCLUSIONS

Perioperative ultrasonography was used to delineate and facilitate removal of an unusual slab fragment of C2, through a minimally sized arthrotomy. Despite the presence of pancarpal osteoarthritis and partial involvement of the medial collateral ligament, the prognosis appeared to be satisfactory for this pleasure riding horse.

CLINICAL RELEVANCE

Ultrasonographic guidance may be used to optimize the approach to C2 articular bony fragments that may not be observed using arthroscopy.